Inflammatory bowel disease a risk factor for VTE in pregnant women

Inflammatory bowel disease increased risk for venous thromboembolism, or VTE, among women during pregnancy and postpartum, study data from Denmark showed.

“Inflammatory bowel disease is a known risk factor for both first-time and recurrent VTE,” Anette T. Hansen, of the department of clinical epidemiology at Aarhus University Hospital, Denmark, and colleagues wrote. “Little information is available on inflammatory bowel disease as a risk factor for VTE during pregnancy and the postpartum period. Earlier studies have shown an excess risk of VTE for inflammatory bowel disease patients during pregnancy, but these studies are limited by imprecise estimates and potential selection bias.”

The researchers performed a nationwide population-based cohort study of all deliveries between 1980 and 2013, gathering data from the Danish National Patient Registry and the Medical Birth Registry. Hansen and colleagues calculated incidence rates per 1,000 person-years, as well as crude and adjusted relative risks with 95% confidence intervals for VTE for women with inflammatory bowel disease compared with women without the disease.

Of 1,978,701 deliveries among 1,046,754 women, Hansen and colleagues identified 3,465 VTE events during pregnancy, and another 1,302 events in the postpartum period. Incidence rates of VTE during pregnancy was higher among women with inflammatory bowel disease than those without (4.2 per 1,000 person years vs. 2.41), which corresponded to an RR of 1.72 (95% CI, 1.22-2.43). After researchers adjusted for maternal age and smoking for pregnancies during 1991 to 2013, the RR was 1.67 (95% CI, 1.15-2.41). Researchers found inflammatory bowel disease associated with a 2.64 RR (95% CI, 1.69-4.14) of experiencing VTE while pregnant.

Women with inflammatory bowel disease experienced a higher incidence rate for postpartum VTE than women without it (7.03 vs. 2.88; adjusted RR, 2.10; 95% CI, 1.33-3.3).

“Our study showed that inflammatory bowel disease is a risk factor for VTE during pregnancy and the postpartum period,” the researchers wrote. “In addition, acute admission for inflammatory bowel disease flares seems to be associated with an excess risk of VTE. This underlines that proper disease control before conception is pivotal in minimizing the risk of VTE.” – by Andy Polhamus

Disclosure: The researchers report no relevant financial disclosures.